Bichromophoric cyano-containing methine dyes and transfer thereof

ABSTRACT

Methine transfer dyes have the formula ##STR1## where L is a bridge member which does not permit any conjugation of π-electrons between Z and Y, 
     X is cyano, C 1  -C 6  -alkoxycarbonyl or C 1  -C 6  -monoalkylcarbamoyl, wherein alkyl may in each case be interrupted by oxygen atoms, or is C 5  -C 7  -cycloalkoxycarbonyl, C 5  -C 7  -monocycloalkylcarbamoyl, phenoxycarbonyl or monophenylcarbamoyl, and 
     Y and Z are each independently of the other aminophenylene, which may be benzo-fused, or heterocyclyl.

This is a division, of application Ser. No. 08/199,355, filed on Feb.18, 1994, which is a continuation of application Ser. No. 07/851,779,filed Mar. 16, 1992, now abandoned, which is a continuation ofapplication Ser. No. 07/650,220, filed Feb. 4, 1991, now abandoned.

The present invention relates to novel methine dyes of the formula I##STR2## where

L is a bridge member which does not permit any conjugation ofπ-electrons between Z and Y,

X is identical or different in its two appearances, denoting in eachcase cyano, C₁ -C₆ -alkoxycarbonyl or C₁ -C₆ -monoalkylcarbamoyl,wherein alkyl may in each case be interrupted by 1 or 2 oxygen atoms, orC₅ -C₇ -cycloalkoxycarbonyl, C₅ -C₇ -monocycloalkylcarbamoyl,phenoxycarbonyl or monophenylcarbamoyl, and

Z and Y are identical or different and, together with the bridge memberL, are each independently of the other a radical of the formula ##STR3##where

n is 0 or 1,

R¹ and R⁵ are identical or different and each is independently of theother alkyl, alkoxyalkyl, alkoxycarbonylalkyl or alkanoyloxyalkyl, whichmay each have up to 10 carbon atoms and be hydroxyl- orcyano-substituted, hydrogen, benzyl, cyclohexyl, phenyl or tolyl,

R² and R³ are identical or different and each is independently of theother hydrogen, C₁ -C₈ -alkyl, C₁ -C₆ -alkoxy, C₁ -C₆ -alkanoylamino orC₁ -C₆ -alkylsulfonylamino,

R⁴ is hydrogen, halogen, C₁ -C₈ -alkyl, unsubstituted or C₁ -C₄ -alkyl-or C₁ -C₄ -alkoxy-substituted phenyl, unsubstituted or C₁ -C₄ -alkyl- orC₁ -C₄ -alkoxy-substituted benzyl, cyclohexyl, thienyl or --NHR¹, whereR¹ is as defined above, and

R⁶ is hydrogen or C₁ -C₈ -alkyl.

Bichromophoric methine dyes with dicyanovinyl groups are known forexample from GB-A- 201 925, U.S. Pat. No. 3,553,245, DE-A-1 569 678,DE-A-2 519 592 and DE-A-3 020 473.

It is an object of the present invention to provide novel bichromophoricmethine dyes which should have advantageous application properties.

We have found that this object is achieved by the methine dyes of theformula I defined at the beginning.

The bridge member L, which does not permit any conjugation ofπ-electrons between Z and Y, generally conforms to the formula

    --E.sup.1 --D--E.sup.2 --

where

D is a chemical bond, oxygen, --SO₂ --, --O--CO--O--, 1,4-cyclohexylene,phenylene, --O--CO--(CH₂)_(p) --CO--O, --O--(CH₂)_(m) --O--, ##STR4##where P is from P to 10 and m is from 2 to 10, ##STR5##

E¹ and E² are identical or different and each is independently of theother a chemical bond or C₁ -C₁₅ -alkylene.

Any alkyl or alkylene appearing in the abovementioned formulae may beeither straight-chain or branched.

A suitable R¹, R², R³, R⁴, R⁵ or R⁶ is for example methyl, ethyl,propyl, isopropyl, butyl, isobutyl, secbutyl, tert-butyl, pentyl,isopentyl, neopentyl, tertpentyl, hexyl, 2-methylpentyl, heptyl, octyl,2-ethylhexyl or isooctyl.

R¹ and R⁵ may each also be for example nonyl, isononyl, decyl, isodecyl,2-methoxyethyl, 2-ethoxyethyl, 2-propoxyethyl, 2-butoxyethyl, 2- or3-methoxypropyl, 2- or 3-ethoxypropyl, 2- or 3-propoxypropyl, 2- or3-butoxypropyl, 4-methoxybutyl, 4-ethoxybutyl, 4-butoxybutyl,2-cyanoethyl, 3-cyanopropyl, 4-cyanobutyl, 2-hydroxyethyl, ##STR6##

R⁴ may also be for example phenyl, 2- , 3- or 4-methylphenyl, 2- or4-isopropylphenyl, 2-butylphenyl, 2-, 3- or 4-methoxyphenyl,2-propoxyphenyl, 4-butoxyphenyl, 2-(but-2-oxy)phenyl, benzyl, 2-, 3- or4-methylbenzyl, 2-, 3- or 4-methoxybenzyl, fluorine, chlorine, bromine,2-thienyl or 3-thienyl.

R² and R³ may each also be methoxy, ethoxy, propoxy, isopropoxy, butoxy,isobutoxy, sec-butoxy, pentyloxy, isopentyloxy, neopentyloxy, hexyloxy,formylamino, acetylamino, propionylamino, butyrylamino,methylsulfonylamino, ethylsulfonylamino, propylsulfonylamino,isopropylsulfonylamino or butylsulfonylamino.

X is for example methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl,isopropoxycarbonyl, butoxycarbonyl, 2-methoxyethoxycarbonyl,methylcarbamoyl, ethylcarbamoyl, 2-methoxyethylcarbamoyl,cyclopentyloxycarbonyl, cyclohexyloxycarbonyl, cycloheptyloxycarbonyl,cyclopentylcarbamoyl, cyclohexylcarbamoyl or cycloheptylcarbamoyl.

E¹ and E² are each for example methylene, 1,2-ethylene, ethylidene,1,2-or 1,3-propylene or 1,4-, 1,3- or 2,3-butylene.

D is for example ##STR7##

Preference is given to methine dyes of the formula I in which Z and Yeach conform to the formula IIa, IIb, IIc, IId, IIe, IIf or IIg.

Preference is further given to methine dyes of the formula I in which

R¹ and R⁵ are each independently of the other hydrogen, unsubstituted orcyano- or acetyl-substituted C₁ -C₆ -alkyl or cyclohexyl,

R² and R³ are each independently of the other hydrogen, methyl, methoxyor acetylamino,

R⁴ is hydrogen, C₁ -C₆ -alkyl or unsubstituted or methyl- ormethoxy-substituted phenyl, 2-thienyl or 3-thienyl, and

R⁶ is hydrogen or C₁ -C₆ -alkyl.

Particular preference is given to methine dyes of the formula I in whichthe bridge member L has the formula

    --E.sup.1 --D--E.sup.2 --

where

E¹ and E² are each independently of the other C₁ -C₄ -alkylene and

D is a chemical bond, oxygen, --SO₂ --, --O--CO--(CH₂)_(p) --CO--O,##STR8## where p is from 2 to 4 and m is from 6 to 10, ##STR9##

Particular preference is further given to methine dyes of the formula Iin which X is cyano.

The methine dyes I according to the present invention can be obtained ina conventional manner, for example as described in GB 1,201,925, U.S.Pat. No. 3,553,245, DE-A-1,569,678, DE-A-2,519,592, DE-A-3,020,473, U.S.Pat. No. 2,889,335 and EP-A-284,560.

A preferred procedure comprises for example first linking the donorgroups Z and Y together by means of an appropriate bridge member andthen preparing from the resulting intermediates the methine dyes I byincorporation of cyanovinyl groups.

By way of illustration see the following synthesis schemes for preparingmethine dyes I (where Z and Y are in each case as defined above):

a) synthesis of dye intermediates ##STR10##

b) incorporation of cyanovinyl group ##STR11##

Other dye intermediates can be converted in the same way.

The novel dyes I are highly soluble in organic solvents.

It is a further object of the present invention to provide a novelprocess for the thermal transfer of dyes.

In the thermotransfer printing process, a transfer sheet which containsa thermally transferable dye in one or more binders on a support with orwithout suitable assistants is heated from the back with an energysource, for example a thermal printing head, in short pulses (lastingfractions of a second), causing the dye to migrate out of the transfersheet and to diffuse into the surface coating of a receiving medium. Theessential advantage of this process is that the amount of dye to betransferred (and hence the color gradation) is readily controllablethrough adjustment of the energy supplied by the energy source.

In general, color recording is carried out using the three subtractiveprimaries yellow, magenta and cyan (with or without black). To ensureoptimal color recording, the dyes must have the following properties:

ready thermal transferability,

little tendency to migrate within or out of the surface coating of thereceiving medium at room temperature,

high thermal and photochemical stability and resistance to moisture andchemical substances,

suitable hues for subtractive color mixing,

a high molar absorption coefficient,

no tendency to crystallize out on storage of the transfer sheet.

From experience these requirements are very difficult to meet at one andthe same time.

For this reason, most of the existing thermal transfer printing dyes donot meet the required property profile.

We have found that the further object is achieved by a process fortransferring a bichromophoric methine dye from a transfer to a sheet ofplastic-coated paper with the aid of an energy source, which comprisesusing a transfer on which there is or are one or more dyes of theformula I ##STR12## where

L is a bridge member which does not permit any conjugation of πelectronsbetween Z and Y,

X is identical or different in its two appearances, denoting in eachcase cyano, C₁ -C₆ -alkoxycarbonyl or C₁ -C₆ -monoalkylcarbamoyl,wherein alkyl may in each case be interrupted by 1 or 2 oxygen atoms, orC₅ -C₇ -cycloalkoxycarbonyl, C₅ -C₇ -monocycloalkylcarbamoyl,phenoxycarbonyl or monophenylcarbamoyl, and

Z and Y are identical or different and, together with the bridge memberL, are each independently of the other a radical of the formula##STR13## where

n is 0 or 1,

R¹ and R⁵ are identical or different and each is independently of theother alkyl, alkoxyalkyl, alkoxycarbonylalkyl or alkanoyloxyalkyl, whichmay each have up to 10 carbon atoms and be hydroxyl-orcyano-substituted, hydrogen, benzyl, cyclohexyl, phenyl or tolyl,

R² and R³ are identical or different and each is independently of theother C₁ -C₈ -alkyl, C₁ -C₆ -alkoxy, C₁ -C₆ -alkanoylamino or C₁ -C₆-alkylsulfonylamino,

R⁴ is hydrogen, halogen, C₁ -C₈ -alkyl, unsubstituted or C₁ -C₄ -alkyl-or C₁ -C₄ -alkoxy-substituted phenyl, unsubstituted or C₁ -C₄ -alkyl- orC₁ -C₄ -alkoxy-substituted benzyl, cyclohexyl, thienyl or -NHR¹, whereR¹ is as defined above, and

R⁶ is hydrogen or C₁ -C₈ -alkyl.

Compared with the dyes used in existing processes, the dyes transferredin the process according to the invention are notable in general forimproved fixation in the receiving medium at room temperature, readierthermal transferability, higher lightfastness, higher stability tomoisture and chemical substances, better solubility in organic solvents,higher inked ribbon stability and higher purity of hue.

It is also surprising that the dyes of the formula I are readilytransferable and that they have a high inked ribbon stability, despitetheir high molecular weight.

The existing thermotransfer printing systems use mixtures ofmonochromophoric dyes to absorb about one third of the incident whitelight each in the cyan and in particular in the magenta region. Thispresents the problem that the dyes used must have exactly the sametransfer characteristics to ensure that the same amount of dye istransferred to the acceptor for a given power output of the thermalprinting head. The process according to the present invention does notsuffer from these disadvantages. The result is, for example in the caseof trichromic systems, an improved black print.

Owing to their high molar extinction coefficients and their highbrilliance, the dyes of the formula I employed in the novel process areadvantageously suitable for preparing a trichromatic system as requiredfor subtrative color mixing.

In addition, the ready transferability permits wide variation of thereceiver or acceptor plastics, and thus makes possible very efficientadaptation of the dyes within the overall system of donor/receiver.

To prepare the dye transfers required in the process according to thepresent invention, the dyes are incorporated into a suitable organicsolvent or solvent mixture together with one or more binders andpossibly further assistants to form a printing ink in which the dye ispreferably present in a molecularly dispersed, dissolved, form. Theprinting ink is then applied to an inert support by knife coating anddried in air.

Suitable organic solvents for the dyes I are for example those in whichthe solubility of the dyes I at 20° C. is greater than 1% by weight,preferably greater than 5% by weight.

Examples are ethanol, propanol, isobutanol, tetrahydrofuran, methylenechloride, methyl ethyl ketone, cyclopentanone, cyclohexanone, toluene,chlorobenzene and mixtures thereof.

Suitable binders are all resins or polymer materials which are solublein organic solvents and are capable of binding the dye to the inertsupport in a form in which it will not rub off. Preference is given inparticular to those binders which, after the printing ink has dried inair, hold the dye in a clear, transparent film in which no visiblecrystallization of the dye occurs.

Examples of such binders are cellulose derivatives, e.g.methylcellulose, ethylcellulose, ethylhydroxyethylcellulose,hydroxypropylcellulose, cellulose acetate and cellulose acetobutyrate,starch, alginates, alkyd resins, vinyl resins, polyvinyl alcohol,polyvinyl acetate, polyvinyl butyrate and polyvinylpyrrolidones. It isalso possible to use polymers and copolymers of acrylates or derivativesthereof, such as polyacrylic acid, polymethyl methacrylate orstyrene/acrylate copolypolyester resins, polyamide resins, polyurethaneresins or natural CH resins, such as gum arabic. Other suitable bindersare described for example in DE-A-3,524,519.

Preferred binders are ethylcellulose, ethylhydroxyethylcellulose,polyvinyl butyrate and polyvinyl acetate.

The weight ratio of binder:dye is in general within the range from 1:1to 10:1.

Suitable assistants are for example release agents as mentioned inEP-A-227,092, EP-A-192,435 and the patent applications cited therein. Itis also possible to include in particular organic additives whichprevent the transfer dyes from crystallizing out in the course ofstorage or heating of the inked ribbon, for example cholesterol orvanillin.

Inert support materials are for example tissue, blotting or parchmentpaper and plastics films possessing good heat resistance, for examplemetallized or unmetallized polyester, polyamide or polyimide. The inertsupport may additionally be coated on the side facing the thermalprinting head with a lubricant or slipping layer in order that adhesionof the thermal printing head to the support material may be prevented.Suitable lubricants are described for example in EP-A-216,483 andEP-A-227,095. The thickness of the support is in general from 3 to 30μm, preferably from 5 to 10 μm.

The dye-receiving medium can be basically any heat resistant plasticslayer having affinity for dyes to be transferred, for example a modifiedpolycarbonate or polyester. Suitable recipes for the receiving layercomposition are described in detail for example in EP-A-227,094,EP-A-133,012, EP-A-133,011, EP-A-111,004, JP-A-199,997/1986,JP-A-283,595/1986, JP-A-237,694/1986 and JP-A-127,392/1986.

Transfer is effected by means of an energy source, for example a laseror a thermal printing head, which must be heatable to ≧300° C. in orderthat dye transfer may take place within the time range t: 0<t<15 msec.In the course of the transfer, the dye migrates out of the transfersheet and diffuses into the surface coating of the receiving medium.

The dyes according to the present invention are also advantageous forcoloring synthetic materials, for example polyesters, polyamides orpolycarbonates.

The Examples which follow further illustrate the present invention.Percentages are by weight, unless otherwise stated.

Preparation of Methine Dyes EXAMPLE A ##STR14##

50 g of 1,9-dibromononane, 58.1 g of ethyl 4-hydroxybenzoate and 94.2 gof potassium carbonate were suspended at room temperature in 500 ml ofN,N-dimethylformamide (anhydrous), and the suspension was then heated at100°C. until starting material was no longer detectable by thin layerchromatography. After cooling, the reaction mixture was filtered withsuction, and the solvent was removed under reduced pressure. The residuewas recrystallized from methanol (37.4 g of pure substance), admixedwith 300 ml of ethanol and added to a mixture of 19.9 g of potassiumhydoxide in 260 ml of ethanol, and the resulting mixture was raised tothe reflux point. After complete hydrolysis (check by TLC), the mixturewas cooled to room temperature and filtered with suction, and theresidue was suspended in water, acidified with hydrochloric acid,filtered off again with suction and washed neutral. This gave 28.3 g ofpure substance.

¹ H-NMR (CDCl₃, TMS): δ=1.10-1.90 (m, 14H, CH₂), 4.05 (t, 4H, OCH₂),7.00 (d, 4H, aromat-H), 7.90 (d, 4H, aromat-H), 12.15 (s, 2H, COOH) ppm.

28 g of the product obtained were suspended in 120 ml of thionylchloride, and the suspension was refluxed until solution was complete.After the reaction had ended, the solution was cooled down to roomtemperature, and the product was precipitated with petroleum ether,filtered off with suction, washed with petroleum ether (IR: COCl,1760-1740 cm⁻¹) and then dissolved in 50 ml of methylene chloride. Thissolution was added dropwise to 22.9 g ofN-(2-hydroxyethyl)-N-ethyl-3-methylaniline, a spatula tip of4-dimethylaminopyridine and 6.5 g of triethylamine in 50 ml of anhydrousmethylene chloride at 0°-5°C. Stirring was then continued at roomtemperature until the reaction had ended. The reaction mixture wasstirred into ice-water, acidified with dilute hydrochloric acid andextracted with methylene chloride. The organic phase was washed neutralwith water and dried, and the solvent was removed under reduced pressure(yield: 42 g, R_(f) value: 0.32 5:1 v/v toluene/ethyl acetate-TLCaluminum sheets, silica gel 60 F₂₅₄ from E. Merck).

EXAMPLE B ##STR15##

7.2 g of the compound of Example A were dissolved in 20 ml of anhydrousN,N-dimethylformamide, and 2.6 g of tetracyanoethylene were added alittle at a time with stirring in the course of 10 minutes. Oncompletion of the addition, the mixture was heated at 55°-60°C. for 15minutes, then cooled to room temperature and stirred into 100 ml ofice-water. The oily dye precipitate was separated off, washed withwater, 20% strength by weight sodium sulfite solution and once more withwater, sucked dry and taken up in 250 ml of acetone. After filtration,the solvent was removed under reduced pressure, and the target productwas purified by chromatography (silica gel/toluene/ethyl acetate).

Yield: 7.8 g

λ_(max) (CH₂ Cl₂): 539 nm

R_(f) value (5:1 v/v toluene/ethyl acetate): 0.26

IR (film): δ=3050, 3000, 2960, 2240, 1700 cm⁻¹.

The same method was used to obtain the following compounds C and D:

EXAMPLE C ##STR16##

λ_(max) (CH₂ Cl₂): 502 nm

R_(f) value (ethyl acetate): 0.52

EXAMPLE D ##STR17##

λ_(max) (CH₂ Cl₂): 526 nm

R_(f) value (5:1 v/v toluene/ethyl acetate): 0.22

Transfer of methine dyes

For a simple quantitative examination of the transfer characteristics ofthe dyes, the thermal transfer was effected with large hotplates insteadof a thermal printing head, the transfer temperature being varied withinthe range 70° C.<T<120° C. while the transfer time was fixed at 2minutes.

α) General recipe for coating the support with dye:

1 g of binder was dissolved in 8 ml of 8:2 v/v toluene/ethanol at40°-50° C. A solution of 0.25 g of dye in 5 ml of tetrahydrofuran wasadded, and any insolubles were filtered off. The print paste thusobtained was applied with an 80 μm doctor blade to a polyester sheet(thickness: 6-10 μm) and dried with a hairdryer.

β) Testing of thermal transferability

The dyes used were tested as follows:

The polyester sheet donor containing the dye under test in the coatedfront was placed face down on commercial receiver paper (specifiedhereinafter) and pressed down. Donor/receiver were then wrapped inaluminum foil and heated between two hotplates at various temperatures T(within the temperature range 70° C.<T<120° C.). The amount of dyediffusing into the bright plastics coating of the receiver isproportional to the optical density (=absorbance A). The latter wasdetermined photometrically. A plot of the logarithm of the absorbance Aof the colored receiver papers measured within the temperature rangefrom 80° to 110° C. against the reciprocal of the corresponding absolutetemperature is a straight line from whose slope it is possible tocalculate the activation energy ΔE_(T) for the transfer experiment:##EQU1##

To complete the characterization, it is additionally possible to readfrom the plots the temperature T* [° C.] at which the absorbance A ofthe colored receiver papers attains the value 1.

The dyes listed in the Tables below were processed according to α), andthe dye-coated transfers obtained were tested for their transfercharacteristics according to β). The Tables show in each case thethermal transfer parameters T* and ΔE_(T), the absorption maxima of thedyes λ_(max) (measured in methylene chloride), the binders used and theweight ratio of dye: binder: assistant.

The key to the abbreviations is as follows:

D=dye

B=binder

EC=ethylcellulose

HCVPP=Hitachi Color Video Print Paper (receiver)

VY-C=Hitachi Color Video Print Paper (receiver)

PBTP=polybutylene terephthalate film (receiver)

SV 100=Color Video Print Paper/Kodak AG (receiver)

                                      TABLE 1                                     __________________________________________________________________________     ##STR18##                                                                    Ex.                      λ.sub.max                                                                            T* ΔE.sub.T                      No.                                                                              Q.sup.1                                                                          Q.sup.2                                                                          Q.sup.3                                                                          Q.sup.4                                                                          Q.sup.5                                                                          Q.sup.6                                                                         Q.sup.7                                                                         Q.sup.8                                                                          [nm]                                                                             D  F:D                                                                              Receiver                                                                           [°C.]                                                                     [kJ/mol]                            __________________________________________________________________________    1  C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                  CN CN H  H H H  524                                                                              EC 1:4                                                                              HCVPP                                                                              60 66                                  2  C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                  CN CN H  H H H  524                                                                              EC 1:4                                                                              PBTP 79 105                                 3  H  C.sub.2 H.sub.5                                                                  CN CN H  H H H  523                                                                              EC 1:4                                                                              HCVPP                                                                              38 43                                  4  H  C.sub.2 H.sub.5                                                                  CN CN H  H H H  523                                                                              EC 1:4                                                                              PBTP 78 65                                  5  C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                  CN CN CH.sub.3                                                                         H H CH.sub.3                                                                         555                                                                              EC 1:4                                                                              SV 100                                                                             83 92                                  6  C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                  CN CN CH.sub.3                                                                         H H CH.sub.3                                                                         555                                                                              EC 1:4                                                                              PBTP 114                                                                              58                                  7  C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                  CN CN H  H H H  524                                                                              EC 1:2                                                                              VY-C 108                                                                              85                                  __________________________________________________________________________

                                      TABLE 2                                     __________________________________________________________________________     ##STR19##                                                                    Ex.                            λ.sub.max                                                                            T* ΔE.sub.T                No.                                                                              Q.sup.1                                                                          Q.sup.2                                                                              Q.sup.3                                                                          Q.sup.4                                                                          Q.sup.5                                                                           Q.sup.6                                                                         Q.sup.7                                                                           Q.sup.8                                                                         [nm]                                                                             D  F:D                                                                              Receiver                                                                           [°C.]                                                                     [kJ/mol]                      __________________________________________________________________________     8 C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                      CN CN H   H H   H 523                                                                              EC 1:4                                                                              HCVPP                                                                              56 55                             9 C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                      CN CN H   H H   H 523                                                                              EC 1:4                                                                              PBTP 83 64                            10 C.sub.2 H.sub.5                                                                   ##STR20##                                                                           CN CN H   H OCH.sub.3                                                                         H 531                                                                              EC 1:4                                                                              HCVPP                                                                              78 84                            11 C.sub.2 H.sub.5                                                                   ##STR21##                                                                           CN CN H   H OCH.sub.3                                                                         H 531                                                                              EC 1:4                                                                              SV 100                                                                             85 225                           12 C.sub.2 H.sub.5                                                                   ##STR22##                                                                           CN CN H   H OCH.sub.3                                                                         H 531                                                                              EC 1:4                                                                              PBTP 104                                                                              85                            13 C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                      CN CN                                                                                ##STR23##                                                                          H   H 528                                                                              EC 1:4                                                                              HCVPP                                                                              84 75                            14 C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                      CN CN                                                                                ##STR24##                                                                          H   H 528                                                                              EC 1:4                                                                              PBTP 127                                                                              40                            __________________________________________________________________________

                                      TABLE 3                                     __________________________________________________________________________     ##STR25##                                                                    Ex.                      λ.sub.max                                                                            T* ΔE.sub.T                      No.                                                                              Q.sup.1                                                                          Q.sup.2                                                                          Q.sup.3                                                                          Q.sup.4                                                                          Q.sup.5                                                                          Q.sup.6                                                                         Q.sup.7                                                                         Q.sup.8                                                                          [nm]                                                                             D  F:D                                                                              Receiver                                                                           [°C.]                                                                     [kJ/mol]                            __________________________________________________________________________    15 C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                  CN CN H  H H H  514                                                                              EC 1:4                                                                              HCVPP                                                                              85 22                                  16 C.sub.2 H.sub. 5                                                                 C.sub.2 H.sub.5                                                                  CN CN H  H H H  514                                                                              EC 1:4                                                                              PBTP 132                                                                              31                                  17 C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                  CN CN H  H H H  514                                                                              EC 1:4                                                                              SV 100                                                                             87 67                                  18 C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                  CN CN CH.sub.3                                                                         H H CH.sub.3                                                                         536                                                                              EC 1:4                                                                              HCVPP                                                                              95 47                                  19 C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                  CN CN CH.sub.3                                                                         H H CH.sub.3                                                                         536                                                                              EC 1:4                                                                              PBTP 170                                                                              26                                  20 C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                  CN CN CH.sub.3                                                                         H H CH.sub.3                                                                         536                                                                              EC 1:2                                                                              SV 100                                                                             89 151                                 21 C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                  CN CN CH.sub.3                                                                         H H CH.sub.3                                                                         536                                                                              PVB                                                                              1:2                                                                              PBTP 126                                                                              77                                  __________________________________________________________________________

                                      TABLE 4                                     __________________________________________________________________________     ##STR26##                                                                    Ex.                        λ.sub.max                                                                             T* ΔE.sub.t                   No.                                                                              Q.sup.1                                                                          Q.sup.2                                                                           Q.sup.3                                                                          Q.sup.4                                                                          Q.sup.5                                                                          Q.sup.6                                                                         Q.sup.7                                                                          Q.sup.8                                                                          [nm]                                                                              D  F:D                                                                              Receiver                                                                           [°C.]                                                                     [kJ/mol]                         __________________________________________________________________________    22 C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                   CN CN H  H H  H  513 EC 1:4                                                                              HCVPP                                                                               79                                                                              83                               23 C.sub. 2 H.sub.5                                                                 C.sub.2 H.sub.5                                                                   CN CN H  H H  H  513 EC 1:4                                                                              PBTP 137                                                                              37                               24 C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                   CN CN H  H H  H  513 EC 1:4                                                                              SV 100                                                                              88                                                                              66                               25 C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                   CN CN CH.sub.3                                                                         H H  CH.sub.3                                                                         535 EC 1:4                                                                              SV 100                                                                             101                                                                              83                               26 C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                   CN CN CH.sub.3                                                                         H H  CH.sub.3                                                                         535 EC 1:4                                                                              PBTP 135                                                                              60                               __________________________________________________________________________

                                      TABLE 5                                     __________________________________________________________________________     ##STR27##                                                                    Ex.                      λ.sub.max                                                                            T*  ΔE.sub.T                     No.                                                                              Q.sup.1                                                                          Q.sup.2                                                                          Q.sup.3                                                                          Q.sup.4                                                                          Q.sup.5                                                                          Q.sup.6                                                                         Q.sup.7                                                                         Q.sup.8                                                                          [nm]                                                                             D  F:D                                                                              Receiver                                                                           [°C.]                                                                      [kJ/mol]                           __________________________________________________________________________    27 C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                  CN CN H  H H H  515                                                                              EC 1:4                                                                              HCVPP                                                                              73  32                                 28 C.sub.2 H.sub.5                                                                  C.sub. 2 H.sub.5                                                                 CN CN H  H H H  515                                                                              EC 1:4                                                                              PBTP 117 49                                 29 C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                  CN CN H  H H H  515                                                                              EC 1:4                                                                              SV 100                                                                             83  90                                 30 C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                  CN CN CH.sub.3                                                                         H H CH.sub.3                                                                         538                                                                              EC 1:4                                                                              SV 100                                                                             88  106                                __________________________________________________________________________

                                      TABLE 6                                     __________________________________________________________________________     ##STR28##                                                                    Ex.                        λ.sub.max                                                                             T* ΔE.sub.T                   No.                                                                              Q.sup.1                                                                          Q.sup.2                                                                           Q.sup.3                                                                          Q.sup.4                                                                          Q.sup.5                                                                          Q.sup.6                                                                         Q.sup.7                                                                          Q.sup.8                                                                          [nm]                                                                              D  F:D                                                                              Receiver                                                                           [°C.]                                                                     [kJ/mol]                         __________________________________________________________________________    31 C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                   CN CN H  H H  H  513 EC 1:4                                                                              HCVPP                                                                              83 69                               32 C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                   CN CN H  H H  H  513 EC 1:4                                                                              PBTP 142                                                                              25                               33 C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                   CN CN H  H H  H  513 EC 1:4                                                                              SV 100                                                                             90 71                               34 C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                   CN CN CH.sub.3                                                                         H H  CH.sub.3                                                                         536 EC 1:4                                                                              SV 100                                                                             98 108                              __________________________________________________________________________

                                      TABLE 7                                     __________________________________________________________________________     ##STR29##                                                                    Ex.                                λ.sub.max  T* ΔE.sub.T        No.  Q.sup.1                                                                          Q.sup.2                                                                            Q.sup.3                                                                          Q.sup.4                                                                            Q.sup.5                                                                          Q.sup.6                                                                           Q.sup.7                                                                         Q.sup.8                                                                            [nm]                                                                             D    F:D                                                                              Receiver                                                                             [°C.]                                                                     [kJ/mol]              __________________________________________________________________________    35   C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                    CN CN   CH.sub.3                                                                         H   H CH.sub.3                                                                           539                                                                              EC   1:4                                                                              PBTP   158                                                                              71                    36   C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                    CN CN   CH.sub.3                                                                         H   H CH.sub.3                                                                           539                                                                              EC   1:4                                                                              HCVPP  119                                                                              38                    37   C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                    CN CN   H  H   H H    517                                                                              EC   1:4                                                                              SV 100 103                                                                              133                   __________________________________________________________________________

                                      TABLE 8                                     __________________________________________________________________________     ##STR30##                                                                    Ex.                      λ.sub.max                                                                            T* ΔE.sub.T                      No.                                                                              Q.sup.1                                                                          Q.sup.2                                                                          Q.sup.3                                                                          Q.sup.4                                                                          Q.sup.5                                                                         Q.sup.6                                                                         Q.sup.7                                                                         Q.sup.8                                                                         n [nm]                                                                             D  F:D                                                                              Receiver                                                                           [°C.]                                                                     [kJ/mol]                            __________________________________________________________________________    38 C.sub.4 H.sub.9                                                                  C.sub.4 H.sub.9                                                                  CN CN H H H H 4 527                                                                              EC 1:4                                                                              HCVPP                                                                              <70                                                                              48                                  39 C.sub.4 H.sub.9                                                                  C.sub.4 H.sub.9                                                                  CN CN H H H H 6 529                                                                              -- -- --   -- --                                  __________________________________________________________________________

                                      TABLE 9                                     __________________________________________________________________________     ##STR31##                                                                    Ex.          λ.sub.max                                                                             T* ΔE.sub.T                                 No.                                                                              Q.sup.1                                                                           Q.sup.2                                                                          n  [nm]                                                                             D  F:D                                                                              Receiver                                                                            [°C.]                                                                     [kJ/mol]                                       __________________________________________________________________________    40 CN  CN 6  544                                                                              -- -- --    -- --                                             __________________________________________________________________________

                                      TABLE 10                                    __________________________________________________________________________    Ex.                                                                           No.                                                                              Formula                                                                    __________________________________________________________________________    41                                                                                ##STR32##                                                                 42                                                                                ##STR33##                                                                 43                                                                                ##STR34##                                                                 __________________________________________________________________________                          Ex.                                                                              λ.sub.max                                                                            T*  ΔE.sub.T                                           No.                                                                              [nm]                                                                             D  F:D                                                                              Receiver                                                                           [°C.]                                                                      [kJ/mol]                           __________________________________________________________________________                          41 542                                                                              EC 1:2                                                                              HCVPP                                                                              112 62                                                       42 530                                                                              EC 1:2                                                                              HCVPP                                                                              92  19                                                       43 549                                                                              EC 1:2                                                                              HCVPP                                                                              97  45                                 __________________________________________________________________________

The same method can be used to transfer the following methine dyes:

    __________________________________________________________________________    Example No.                                                                   __________________________________________________________________________    44                                                                                      ##STR35##                                                           45                                                                                      ##STR36##                                                           46                                                                                      ##STR37##                                                           47                                                                                      ##STR38##                                                           48                                                                                      ##STR39##                                                           49                                                                                      ##STR40##                                                           50                                                                                      ##STR41##                                                           51                                                                                      ##STR42##                                                           52                                                                                      ##STR43##                                                           53                                                                                      ##STR44##                                                           54                                                                                      ##STR45##                                                           55                                                                                      ##STR46##                                                           56                                                                                      ##STR47##                                                           57                                                                                      ##STR48##                                                           58                                                                                      ##STR49##                                                           59                                                                                      ##STR50##                                                           60                                                                                      ##STR51##                                                           61                                                                                      ##STR52##                                                           62                                                                                      ##STR53##                                                           __________________________________________________________________________

We claim:
 1. A methine dye of the formula I ##STR54## where L is abridge member which does not permit any conjugation of π-electronsbetween Z and Y of the formula

    --E'--D--E.sup.2 --

wherein D is a chemical bond, oxygen, --SO₂ -- --O--CO--O--,1,4-cyclohexylene, phenylene, --O--CO--(CH₂)_(p) --CO--O, --O--(CH₂)_(m)--O--, ##STR55## where p is from 1 to 10 and m is from 2 to 10,##STR56## E¹ and E² are identical or different and each is independentlyof the other a chemical bond or C₁ -C₁₅ -alkylene, X is identical ordifferent in its two appearances, denoting in each case cyano, C₁ -C₆-alkoxycarbonyl or C₁ C₆ -monoalkylcarbamoyl, wherein alkyl may in eachcase be interrupted by 1 or 2 oxygen atoms, or C₅ -C₇-cycloalkoxycarbonyl, C₅ -C₇ -monocycloalkylcarbamoyl, phenoxycarbonylor monophenylcarbamoyl, and Z and Y are identical or different and,together with the bridge member L, are each independently of the other aradical of the formula ##STR57## where R² and R³ are identical ordifferent and each is independently of the other hydrogen, C₁ -C₈-alkyl, C₁ -C₆ alkoxy, C₁₋₆ alkanoylamino or C₁ -C₆ -alkylsulfonylamino.2. The methine dye of claim 1, wherein D is --SO₂ --.
 3. The methine dyeof claim 1, wherein X is cyano.